# -*- coding: utf-8 -*- ''' Created on May 19, 2012 @author: Edison ''' from math import sqrt # A dictionary of movie critics and their ratings of a small # set of movies critics={'Lisa Rose': {'Lady in the Water': 2.5, 'Snakes on a Plane': 3.5, 'Just My Luck': 3.0, 'Superman Returns': 3.5, 'You, Me and Dupree': 2.5, 'The Night Listener': 3.0}, 'Gene Seymour': {'Lady in the Water': 3.0, 'Snakes on a Plane': 3.5, 'Just My Luck': 1.5, 'Superman Returns': 5.0, 'The Night Listener': 3.0, 'You, Me and Dupree': 3.5}, 'Michael Phillips': {'Lady in the Water': 2.5, 'Snakes on a Plane': 3.0, 'Superman Returns': 3.5, 'The Night Listener': 4.0}, 'Claudia Puig': {'Snakes on a Plane': 3.5, 'Just My Luck': 3.0, 'The Night Listener': 4.5, 'Superman Returns': 4.0, 'You, Me and Dupree': 2.5}, 'Mick LaSalle': {'Lady in the Water': 3.0, 'Snakes on a Plane': 4.0, 'Just My Luck': 2.0, 'Superman Returns': 3.0, 'The Night Listener': 3.0, 'You, Me and Dupree': 2.0}, 'Jack Matthews': {'Lady in the Water': 3.0, 'Snakes on a Plane': 4.0, 'The Night Listener': 3.0, 'Superman Returns': 5.0, 'You, Me and Dupree': 3.5}, 'Toby': {'Snakes on a Plane':4.5,'You, Me and Dupree':1.0,'Superman Returns':4.0}} # Returns a distance-based similarity score for person1 and person2 def sim_distance(prefs,person1,person2): # Get the list of shared_items si={} for item in prefs[person1]: if item in prefs[person2]: si[item]=1 # if they have no ratings in common, return 0 if len(si)==0: return 0 # Add up the squares of all the differences sum_of_squares=sum([pow(prefs[person1][item]-prefs[person2][item],2) for item in prefs[person1] if item in prefs[person2]]) return 1/(1+sum_of_squares) # Returns the Pearson correlation coefficient for p1 and p2 def sim_pearson(prefs, p1, p2): # Get the list of mutually rated items si = {} for item in prefs[p1]: if item in prefs[p2]: si[item] = 1 # Find the number of elements n = len(si) # if they are no ratings in common, return 0 if n == 0: return 0 # Add up all the preferences sum1 = sum([prefs[p1][it] for it in si]) sum2 = sum([prefs[p2][it] for it in si]) # Sum up the squares sum1Sq = sum([pow(prefs[p1][it], 2) for it in si]) sum2Sq = sum([pow(prefs[p2][it], 2) for it in si]) # Sum up the products pSum = sum([prefs[p1][it] * prefs[p2][it] for it in si]) # Calculate Pearson score num=pSum-(sum1*sum2/n) den=sqrt((sum1Sq-pow(sum1,2)/n)*(sum2Sq-pow(sum2,2)/n)) if den==0: return 0 r = num/den return r if __name__ == "__main__": #print sim_distance(critics, 'Lisa Rose', 'Jack Matthews') import pickle name = u'乔治克鲁尼' sex = u'男' print name.encode('utf-8') my_dict = {} my_dict[name.encode('utf-8')] = sex for key in my_dict: print key print my_dict